Systems and methods for removing oil from fluid streams

ABSTRACT

The invention provides systems and methods for removing a target oil from an aqueous fluid stream using a capture medium. In embodiments, the capture medium can comprise an anchor substrate and a modifier technology supported on the anchor substrate, where the modifier technology complexes with the oil to form a removable complex.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/669,104, filed Nov. 5, 2012, which is a continuation of InternationalApplication No. PCT/US11/35305, which designated the United States andwas filed on May 5, 2011, published in English, which claims the benefitof U.S. Provisional Application Ser. No. 61/331,796 filed May 5, 2010,U.S. Provisional Application Ser. No. 61/349,648 filed May 28, 2010 andU.S. Provisional Application Ser. No. 61/355,020 filed Jun. 15, 2010.The entire contents of the above-referenced applications areincorporated by reference herein.

FIELD OF THE APPLICATION

The application relates generally to removing oil from fluid streams.

BACKGROUND

Oil can be found admixed with a number of fluid streams, requiring itsseparation. For example, tailings ponds from oil sands processingcontain a heavy oil called bitumen. Separating the bitumen from thetailings water can offer economic and environmental advantages. Refineryeffluents can contain oil admixed with an aqueous stream. Bilge waterand other types of industrial waste water can contain a quantum of oiladmixed therein. Water used for or produced by hydraulic fracturing inoil or gas reservoirs can also contain a hydrocarbon component, forexample crude oil. Water that is co-produced during oil production istypically treated by chemical and mechanical separation practices torecover the oil values and to minimize the contamination of the producedwater effluent stream. After this conventional treatment, it isdesirable to apply secondary treatment to meet environmental andregulatory objectives. Oil contaminated waters present challenges totreatment methods such as reverse osmosis, nanofiltration,ultrafiltration, diatomaceous earth filtration, activated carbontreatment, and the like. Removal of light chain and heavy chainhydrocarbons from aqueous fluid streams, including aliphatics,aromatics, and mixtures thereof, poses a significant challenge for oildrilling and production facilities and associated water treatmentoperations. It would be advantageous to provide efficient andcost-effective systems for separating the oil from the fluid stream.

As a salient example of oil contaminating an aqueous fluid stream, theDeepwater Horizon oil spill in 2010 demonstrated the challenges ofseparating these two components, and the damage that such oilcontamination can cause. Oil floating in the open water decimatessea-faring birds and damages fish populations. When the oil approachesthe shoreline, it coats the beaches, estuaries and wetlands, devastatingliving things that depend upon those habitats and wreaking immeasurableeconomic havoc. Once released, an oil spill proves very difficult tocontain or deflect. Even more difficult is the task of removing itadequately from environmental contact.

Current methods of spill containment include physical and chemicalapproaches. For physical containment, booms or socks can be used, whichact as barriers and which can have oil absorption capabilities. However,these mechanisms lose significant efficacy in the open ocean whenconditions are rough, a situation that is not uncommon where oil spillsoccur. For chemical treatments, a variety of dispersants have beendevised. Two significant drawbacks limit the efficacy of dispersanttechnologies. First, it is difficult to form stable microemulsions ofthe heavy crude that constitutes the spill. In essence, the oily blobsin the spill simply break up into smaller blobs when they encounter thedispersant, but the blobs do not disappear from the water surface. Thesmaller blobs can continue towards the shoreline with damaging effect.Second, even if stable microemulsions were achievable with a givendispersant, it is not clear that the emulsified system would cause lessdamage than the intact oil blobs. In fact, the emulsified oil systemcould spread more rapidly and widely, potentially amplifying thedestruction.

To mitigate the potential damage of an open-water spill, it is desirableto cause the floating crude oil or other oily substance to be rapidlysequestered, for example by entrapment in a floating substrate.Alternatively, the floating oil or crude oil can be caused to sinkrapidly and completely to the sea floor before it affects the marinepopulation in the open ocean, and before it reaches landfall. Suchapproaches can offer the best chance of protecting vulnerable coastalfisheries and other ecosystems from the devastating impact of anopen-ocean oil spill.

SUMMARY

Disclosed herein, in embodiments, are systems for removing a target oilfrom an aqueous fluid stream, comprising: a capture medium thatcomplexes with the oil to form a removable complex that can be removedfrom the aqueous fluid stream, thereby removing the target oil from theaqueous fluid stream, wherein the capture medium comprises an anchorsubstrate and a modifier technology supported on the anchor substrate,the modifier technology complexing with the oil to form the removablecomplex. In embodiments, the anchor substrate has a density greater thanthat of the oil. In other embodiments, the anchor substrate has adensity less than that of the oil. In embodiments, the anchor substratecomprises a plurality of loose particles or fibers. In embodiments, theanchor substrate is formed as a formed article. The formed article canbe selected from the group consisting of a sheet, a fibrous network, ascreen, a plurality of elongated fibers, an agglomeration of particulatematter, a mop, a boom, an open-cell foam mass, a closed-cell foam mass,and a swab. In embodiments, the modifier technology comprises anoleophilic capture substance. In embodiments, the modifier technologyfurther comprises an attachment technology that modifies the surface ofthe anchor substrate to attach the oleophilic capture substance thereto.In embodiments, the attachment technology comprises a physicalmodification of the surface of the anchor substrate. In embodiments, theattachment technology comprises a mechanical mechanism for adhering theoleophilic capture substance to the surface of the anchor substrate. Inembodiments, the attachment technology comprises an attachment chemicalthat attaches the oleophilic capture substance to the surface of theanchor substrate.

Also disclosed herein, in embodiments, are methods for removing a targetoil from an aqueous fluid stream, comprising: preparing a capture mediumcomprising an anchor substrate and a modifier technology supported onthe anchor substrate, wherein the modifier technology complexes with thetarget oil to form a removable complex, deploying the capture mediuminto contact with the target oil, directing the capture medium tocontact the target oil for a contact time such that the capture mediumforms a removable complex with the target oil, removing the removablecomplex from the aqueous fluid stream, thereby removing the target oilfrom the aqueous fluid stream, wherein the step of preparing takes placebefore the step of deploying. In embodiments, the anchor substrate has adensity greater than that of the oil. In embodiments, the anchorsubstrate has a density less than that of the oil. In embodiments, theanchor substrate comprises a plurality of loose particles or fibers. Inembodiments, the anchor substrate is formed as a formed article. Inembodiments, the formed article is selected from the group consisting ofa sheet, a fibrous network, a screen, a plurality of elongated fibers,an agglomeration of particulate matter, a mop, a boom, an open-cell foammass, a closed-cell foam mass, and a swab. In embodiments, the modifiertechnology comprises an oleophilic capture substance. In embodiments,the modifier technology further comprises an attachment technology thatmodifies the surface of the anchor substrate to attach the oleophiliccapture substance thereto. In embodiments, the attachment technologycomprises a physical modification of the surface of the anchorsubstrate. In embodiments, the attachment technology comprises anattachment chemical that attaches the oleophilic capture substance tothe surface of the anchor substrate. The method may further comprise thestep of disposing of the removable complex. Also disclosed herein, inembodiments, are methods for removing a target oil from an aqueous fluidstream, comprising: combining the anchor substrate and a modifiertechnology supported on the anchor substrate to form a capture medium,wherein the modifier technology complexes with the target oil to form aremovable complex, contacting the capture medium with the fluid streambearing the target oil for a contact time such that the capture mediumforms a removable complex with the target oil, and removing theremovable complex from the aqueous fluid stream, thereby removing thetarget oil from the aqueous fluid stream. In embodiments, the step ofcombining takes place simultaneously with or following the step ofcontacting. In embodiments, the step of contacting further includes astep of directing the fluid stream into contact with the capture mediumfor the contact time.

BRIEF DESCRIPTION OF THE FIGURE

The FIGURE provides a graph showing oil absorbance and water absorbancefor various sorbent materials.

DETAILED DESCRIPTION

Disclosed herein are systems and methods for capturing and sequesteringan oily substance admixed with an aqueous fluid stream. As used herein,the term “oily substance” refers without limitation to hydrocarbons,i.e, oils that can be admixed deliberately or inadvertently with anaqueous fluid stream, for example crude oil, refined hydrocarbons,fuels, lubricants, oil spills, water insoluble hydrophobic materials,water soluble fractions of organic matter, resins, and paints, and thelike, or any combination thereof, with the term “hydrocarbon” includingaliphatics, aromatics, and heteroatom-substituted organics, furtherincluding linear, branched and cyclic organic chains. As an example, theoily substance can be dispersed in the fluid stream or contained withinthe fluid stream as one or more identifiable layers. In embodiments, theoily substance can be floating on an aqueous medium, such as crude oilspilled upon an open ocean. In other embodiments, the oily substance canbe emulsified in the aqueous medium or dissolved in the aqueous medium.While embodiments are disclosed herein for treating oil spills such ascrude oil that are released at sea, in other embodiments these systemsand methods may be applied to other oil spills on aqueous surfaces, forexample industrial spills into fresh water reservoirs, or spills ofhydrophobic lubricants, fuels, and the like, from transportationactivities, or oil contained within wastewater derived fromoil-producing, oil-refining or oil-utilizing activities. Any oilysubstance identified for removal from the aqueous fluid stream can alsobe termed a “target oil.”

Disclosed herein, in embodiments, are anchor substrates that aremodified by coating them or otherwise attaching to them an oleophiliccapture substance, whereby the oleophilic capture substance attracts thetarget oil in the oil spill and complexes with it. In embodiments, theresultant complex sinks to the bottom of the ocean or other body ofwater. In other embodiments, the resultant complex floats on the surfaceof the ocean or other body of water, and can be readily skimmed off. Inother embodiments, the resultant complex may neither float nor sink, butnonetheless can be sequestered to separate it (and its complexed targetoil) from the fluid stream. In certain embodiments, the anchor substrateincludes fibers or particles, lending themselves to removal techniqueslike filtration, skimming, vacuuming, and the like. In otherembodiments, the anchor substrate can be formed as a continuous unit oflarger dimensions to which the target oil is complexed, so that theanchor substrate and the attached oil is removed as a unit. As examples,the anchor substrate can be formed as sheets or booms to be applied tothe target oil, as strands or netting to be applied to the target oil,as spheres or other geometric solids to be injected into the target oil,as foamed products made from natural or artificial materials, or thelike. In certain embodiments, the capture medium (i.e., the anchorsubstrate and the modifier technology that it supports) can bepositioned in a fixed location, and the aqueous fluid stream can bedirected into contact with it. In other embodiments, as described above,the capture medium is deployed into contact with the fluid streambearing the target oil. In either case, the capture medium is directedto contact the target oil for a contact time such that the capturemedium forms a removable complex with the target oil. The contact timecan vary, depending on factors such as temperature, exposed surfacearea, and the avidity of attraction between the target oil and thecapture medium.

Provided herein, therefore, are systems and methods for removing atarget oil from an aqueous stream comprising a capture medium thatcomplexes with the target oil to form a removable complex that can beremoved from the fluid stream, thereby removing the target oil from theaqueous fluid stream. The capture medium in these embodiments comprisesan anchor substrate and a modifier technology supported on the anchorsubstrate, the modifier technology complexing with the oil to form theremovable complex. In embodiments, the modifier technology furthercomprises an oleophilic capture substance, which can be attached to thesurface of the anchor substrate with an attachment technology.

In certain embodiments, these systems and methods comprise threecomponents: (1) an anchor substrate, capable of supporting an oleophiliccapture substance that can complex with the target oil to permit itsremoval from the aqueous fluid stream; (2) an oleophilic capturesubstance that has affinity with the crude oil, heavy oil, hydrocarbonor other target oil, so that it complexes with it; and (3) an attachmenttechnology that modifies the surface of the anchor substrate orotherwise attaches the oleophilic capture substance to the anchorsubstrate (such attachment processes being collectively termed “coating”herein, although it is recognized that a variety of surfacemodifications and other mechanisms may effect the attachment of theoleophilic capture substance or substances to the anchor substrate). Theinteraction of the anchor substrate, the capture substance and theattachment technology produces an oleophilic capture medium that cancomplex with the target oil, forming a removable complex that sequestersthe target oil to allow for its separation from the fluid stream.

For example, the anchor substrates bearing the oleophilic capturesubstance can interact with oil spills on a fluid stream like the openocean, e.g., a crude oil spill, forming therewith a removable complexthat sequesters the target oil in a form that allows for its removalfrom the ocean ecosystem, either by flotation or by sinking. In such anembodiment, the anchor substrates could be selected to have a densitythat is useful for allowing the sequestered target oil to be removedeffectively from the ocean ecosystem, either by flotation and subsequentremoval or by sinking. In embodiments, an anchor substrate can beselected that can be supported by the surface tension of the target oilor of the fluid stream, for example a thin fibrous sheet (e.g., a papertowel or an analogous structure made with non-cellulosic fibers) or afoamed sheet, boom, or sponge, whether made from natural or artificialmaterials.

In embodiments, the systems and methods disclosed herein can be used forcapturing and sequestering crude oil that is spilled on the surface ofthe ocean or other salt water body. Crude oil typically has a densitythat is less than that of seawater, so that it floats on the surface. Inembodiments, these systems and methods provide capture media formed fromattaching an oleophilic capture substance to an anchor substrate that isdenser than the crude oil. The oleophilic capture coating of the capturemedium interacts with the crude oil, forming a durable complex that isdenser than the seawater. The capture-medium-crude-oil complex thereforesinks, sequestering the crude oil within the deeper strata of the sea,or on the bottom of the sea if the captured crude complex is ofsufficient density. In embodiments, anchor substrates are selected thathave sufficient density to produce removable complexes that sink to thebottom of the sea. In other embodiments, the anchor substrates areselected to have a density or other physical properties such that theremovable complexes float on the surface of the fluid stream. Inembodiments, these removable complexes can be physically separated fromthe fluid stream, thereby removing the target oil from the fluid stream.In other embodiments, the density of the anchor substrates neitherpredisposes the removable complexes to float nor to sink, butfacilitates their separation from the fluid stream by mechanical orother separation techniques. In other embodiments, the oil containingwater can be contacted with the capture medium by directing the fluidstream into contact with the capture medium, for example by directingthe fluid stream into an inline mix tank containing the capture medium,or by flowing the fluid stream through a pressure vessel or otherhydraulic system that contains the capture medium.

1. Anchor Substrates

As used herein, the term “anchor substrate” refers to a material thatcan be modified to bear on its surface an oleophilic capture substance,in accordance with the systems and methods disclosed herein. An anchorsubstrate can be particulate or fibrous in nature, dimensioned so as tobe collected in large quantities with the target oil attached thereto. Amultitude of finely dimensioned particles or fibers of anchor substratecan thus provide a large surface area for oil attachment. An anchorsubstrate can also be configured as a formed article, for example asolid article like a sheet, a boom, a strand, a network, a foam mass, orthe like. An advantageous surface area can be provided by texturing ofthe surface for a large article, intertwining a plurality of strands orfibers, forming a foam mass, binding together a plurality of smallergeometric shaped articles, and the like. Composites of various anchorsubstrates can be fabricated that are consistent with these systems andmethods.

In embodiments, anchor substrates have a density that is greater thanthe aqueous medium supporting the target oil. For example, anchorsubstrates that have a density of greater than 1.3 g/cc can be used. Inembodiments, the anchor substrates may have a lower density than thefluid stream, or can have a density that is less than the density of thetarget oil. If the density of the anchor substrates is greater than thedensity of the target oil, they will facilitate sinking. In embodiments,dense particles may be selected for modification, so that they settlerapidly. In yet other embodiments, less dense or buoyant substrates maybe selected for modification, so that they rise to the fluid surfaceafter complexing with the fine particulate matter, allowing thecomplexes to be removed via a skimming process rather than asettling-out process, or so that they can be readily filtered out orskimmed off. In embodiments, the anchor substrates can be chosen fortheir low packing density or potential for developing porosity. Adifference in density or particle size facilitates separating solidsfrom the medium if the anchor substrates are dimensioned, for example,as small fibers or particles.

Suitable anchor substrates can be formed from organic or inorganicmaterials, or any mixture thereof. Materials suitable for use as anchorsubstrates can include organic or inorganic substances, or mixturesthereof. In referring to an anchor substrate, it is understood that sucha substrate can be made from a single substance or can be made from acomposite. For example, an anchor substrate can be formed from asubstrate of one type of biomass combined with a substrate of anothertype of biomass. For systems where the sinking of the captured crudecomplexes is desirable, inorganic materials and non-biodegradablematerials would be preferable, lest changes to the substrates themselvesrelease the sequestered oil.

In accordance with these systems and methods, inorganic anchorsubstrates can include one or more materials such as barite, calciumcarbonate, dolomite, calcium sulfate, kaolin, talc, titanium dioxide,sand, diatomaceous earth, aluminum hydroxide, silica, other metal oxidesand the like. Many inorganic materials have the desired density forforming captured crude complexes that will sink. Most notable are sand,barium sulfate, gypsum, clay, calcium carbonate, ferric oxide, alumina,boron nitride, lead sulfide, and numerous other naturally occurring andman-made substances. Cost and abundance can be drivers for selection ofanchor substrates.

In embodiments, ground calcium carbonate (GCC) or precipitated calciumcarbonate (PCC) can be used as an anchor substrate. It can effectivelyattach capture substances having carboxylic acid side groups, such asstyrene copolymers with carboxylic functional groups or fatty acids.

Examples of inorganic anchor substrates include clays such asattapulgite and bentonite. In embodiments, the inorganic compounds canbe vitreous materials, such as ceramic particles, glass, fly ash and thelike. The substrate materials may be solid or may be partially orcompletely hollow. For example, glass or ceramic microspheres may beused as substrates. Vitreous materials such as glass or ceramic may alsobe formed as fibers to be used as substrates. Cementitious materials mayinclude gypsum, Portland cement, blast furnace cement, alumina cement,silica cement, and the like. Carbonaceous materials may include carbonblack, graphite, carbon fibers, carbon microparticles, and carbonnanoparticles, for example carbon nanotubes.

In embodiments, plastic materials may be used as anchor substrates. Boththermoset and thermoplastic resins may be used to form plasticsubstrates. Plastic substrates may be shaped as solid bodies, hollowbodies or fibers, or any other suitable shape. Plastic substrates can beformed from a variety of polymers. A polymer useful as a plasticsubstrate may be a homopolymer or a copolymer. Copolymers can includeblock copolymers, graft copolymers, and interpolymers. In embodiments,suitable plastics may include, for example, addition polymers (e.g.,polymers of ethylenically unsaturated monomers), polyesters,polyurethanes, aramid resins, acetal resins, formaldehyde resins, andthe like. Addition polymers can include, for example, polyolefins,polystyrene, and vinyl polymers. Polyolefins can include, inembodiments, polymers prepared from C₂-C₁₀ olefin monomers, e.g.,ethylene, propylene, butylene, dicyclopentadiene, and the like. Inembodiments, poly(vinyl chloride) polymers, acrylonitrile polymers, andthe like can be used. In embodiments, useful polymers for the formationof substrates may be formed by condensation reaction of a polyhydriccompound (e.g., an alkylene glycol, a polyether alcohol, or the like)with one or more polycarboxylic acids. Polyethylene terephthalate is anexample of a suitable polyester resin. Polyurethane resins can include,e.g., polyether polyurethanes and polyester polyurethanes. Plastics mayalso be obtained for these uses from waste plastic, such aspost-consumer waste including plastic bags, containers, bottles made ofhigh density polyethylene, polyethylene grocery store bags, and thelike. In embodiments, elastomeric materials can be used as substrates.Substrates of natural or synthetic rubber can be used, for example.

Organic anchor substrates can include one or more materials such asstarch, modified starch, polymeric spheres (both solid and hollow), andthe like. For smaller-dimensioned anchor substrates, configured asfibers or particles, for example, sizes can be microscopic orsubmicroscopic, ranging for example from a few nanometers to few hundredmicrons. In certain embodiments, substrates configured as a plurality ofmacroscopic particles or fibers sized in the millimeter range may besuitable. In other embodiments, the anchor substrate is a macroscopicformed article, configured as one or more sheets, booms, networks,elongated fibers, geometric shapes, or any combination thereof.

In embodiments, a substrate can comprise materials such aslignocellulosic material, cellulosic material, minerals, vitreousmaterial, cementitious material, carbonaceous material, plastics,elastomeric materials, and the like. In embodiments, cellulosic andlignocellulosic materials may include wood materials such as woodflakes, wood fibers, wood waste material, wood powder, lignins, orfibers from woody plants. Organic materials can include various forms oforganic waste, including biomass and including particulate matter frompost-consumer waste items such as old tires and carpeting materials.

In embodiments, fibers or fibrous materials can be used as anchorsubstrates. Fibers for use as anchor substrates may be provided in theirnatural dimensions, or they may be processed to fragment them orotherwise change their shape. Preferably, the fibers are highly expandedto maximize surface area and absorbing capacity. Fibers when used asanchor substrates can be amalgamated loosely or tightly, for example toform textiles that are woven or non-woven. Fibers suitable for use asanchor substrates can be of one or more fiber types, i.e., fibers can benatural, synthetic or artificial (i.e., semisynthetic, made by themanipulation of natural substances like cellulose to form materials notfound in nature). Natural fibers can include fibers from animal sources(e.g., wool, hair, silk), fibers from plant sources (e.g., cotton, flax,jute), and fibers from mineral sources (e.g., asbestos, glass).Synthetic and semisynthetic fibers can include fibers made frompolyesters, aramids, acrylics, nylons, polyurethane, polyolefin,polylactides, and the like. In embodiments, semisynthetic fibers caninclude fibers made from cellulose substrates, for example celluloseesters (e.g., cellulose acetate), rayon, bamboo fiber, lyocells, viscoserayon, and the like.

Anchor substrates can be selected from biomass, for example, so thatthey complex with the target oil to form a biomass-oil composite solid.Biomass can be derived from vegetable sources or animal sources. Biomasscan be derived from waste materials, including post-consumer waste,animal or vegetable waste, agricultural waste, sewage, and the like. Inembodiments, the biomass sourced materials are to be processed so thatthey form anchor substrates of an appropriate size for tethering andcombining with the target oil. Substrate sizes of, e.g., 0.01-50millimeters can be used. Long, narrow fibers are another desirable form.Processing methods can include grinding, milling, pumping, shearing, andthe like. For example, hammer mills, ball mills, and rod mills can beused to reduce oversized materials to an appropriate size. Inembodiments, additives might be used in the processing of the anchorsubstrates to improve efficiency, reduce energy requirements, orincrease yield. These processing additives include polymers,surfactants, and chemicals that enhance digestion or disintegration.Optionally, other treatment modalities, such as exposure to cryogenicliquids (e.g., liquid nitrogen or solid carbon dioxide) can be employedto facilitate forming anchor substrates of appropriate size frombiomass. It is understood that biomass-derived anchor substrates can beformed as substrates of any morphology (regular or irregular,plate-shaped, flakes, cylindrical, spherical, needle-like, etc.) or canbe formed as fibers. Fibrous materials may be advantageous in that theyfacilitate dewatering/filtration of the composite material being formedby these systems and methods, and they can add strength to suchcomposite materials. Fibrous materials have the added advantage of theability to form the material into shapes that enable distribution,sorption, and collection of oil.

Vegetable sources of biomass can include fibrous material, particulatematerial, amorphous material, or any other material of vegetable origin.Vegetable sources can be predominately cellulosic, e.g., derived fromcotton, jute, flax, hemp, sisal, ramie, and the like. Vegetable sourcescan be derived from seeds or seed cases, such as cotton or kapok, orfrom nuts or nutshells. Vegetable sources can include the wastematerials from agriculture, such as corn stalks, stalks from grain, hay,straw, or sugar cane (e.g., bagasse). Vegetable sources can includeleaves, such as sisal, agave, deciduous leaves from trees, shrubs andthe like, leaves or needles from coniferous plants, and leaves fromgrasses. Vegetable sources can include fibers derived from the skin orbast surrounding the stem of a plant, such as flax, jute, kenaf, hemp,ramie, rattan, soybean husks, vines or banana plants. Vegetable sourcescan include fruits of plants or seeds, such as coconuts, peach pits,mango seeds, and the like. Vegetable sources can include the stalks orstems of a plant, such as wheat, rice, barley, bamboo, and grasses.Vegetable sources can include wood, wood processing products such assawdust, and wood, and wood byproducts such as lignin.

Animal sources of biomass can include materials from any part of avertebrate or invertebrate animal, fish, bird, or insect. Such materialstypically comprise proteins, e.g., animal fur, animal hair, animalhoofs, and the like. Animal sources can include any part of the animal'sbody, as might be produced as a waste product from animal husbandry,farming, meat production, fish production or the like, e.g., catgut,sinew, hoofs, cartilaginous products, etc. Animal sources can includethe dried saliva or other excretions of insects or their cocoons, e.g.,silk obtained from silkworm cocoons or spider's silk. Animal sources caninclude dairy byproducts such as whey, whey permeate solids, milksolids, and the like. Animal sources can be derived from feathers ofbirds or scales of fish.

Anchor substrate sizes (as measured as a mean diameter) can have a sizeup to few hundred microns, for example a size greater than about 70microns. In certain embodiments, macroscopic anchor substrates up to andgreater than about 1 cm may be suitable. In the case of fibrous anchorsubstrates, the length of the fibers can be significantly greater thanthe diameter. In embodiments, the fibers can be formed into a continuousshape such as a roll, pad, rope, pompom, pillow, blanket, net, and thelike.

In other embodiments, anchor substrates comprising materials such asthose disclosed above can be fabricated as formed articles. For example,a plurality of fibers can be formed as a sheet having large dimensionsrelative to the size of the component fibers. As an example, a papersheet or paper towel can be formed to act as an anchor substrate, or ananalogous article can be formed from non-cellulosic fibers. As anotherexample, a foamed article, such as a boom or a natural or artificialsponge, can be formed as an anchor substrate, with dimensions suitablefor the mass of oil to be removed. A foamed article can be of relativelylarge dimensions, or it can be broken down into foam pieces which act asanchor substrates. Formed substrates comprising anchor substrates can beconfigured and arranged as filters or screens to be used for in-linefluid processing. Such objects, while suitable for in-line fluidprocessing where a fluid stream is directed to contact them, can also bedeployed upon an open body of water to reach a target oil containedtherein. Formed substrates can be configured as elongated masses orintertwined masses of fibers, where the fibers can be of any suitabledimension for their deployment. As examples, the fibers can be extremelylong in comparison to their cross-sectional diameter. The fibers can beof macroscopic dimensions in length, width, or both. The fibers can beintertwined or otherwise interacting with each other, formed as swabs,pompoms, “cotton balls,” and the like. Other shapes, configurations,compositions, and uses of anchor substrates as formed articles will bereadily apparent to those of ordinary skill in the art.

2. Oleophilic Capture Substances

A number of hydrophobic (generally organic) materials can be attached toanchor substrates as capture coatings that can interact with the targetoil to complex it. In embodiments, examples of capture substancesinclude water-insoluble coatings such as waxes, paraffins, oils, crudeoil, mineral oil, rosin, fatty acids, triglycerides, asphaltenes, latexrubber, rubber cement, and the like. In embodiments, examples of capturesubstances also include other hydrophobic species such as naphthenicacid, aromatic carboxylic acid compounds, benzoic acid, the Jeffamines,and the like. In embodiments, examples of capture substances arenon-polar polymers such as polyolefins, polyethylene, polypropylene,SBR, polyisobutylene, polyisoprene, polybutadiene, styrenics andcopolymers, and chitosan can be used.

Capture substances that can be attached covalently to anchor substratesinclude trimethylchlorosilane and other organosilane quaternarycompounds (e.g., the Aegis Microbe “sword” compound). Other covalentlyattached capture substances include alkylketene dimers andalkenylsuccinic anhydrides. Polymers that can act as capture substancesinclude styrene maleic anhydride polymers, styrene-maleic anhydrideimide polymers, styrene-butadiene rubber copolymers, polyisoprene,styrene-isoprene, styrene-butadiene-styrene bloc copolymers,polyisobutylmethacrylate, polyisobutylmethacrylate/linseed oil, alkylacrylate copolymers, styrene maleimide (SMA imide) resins, and the like.Cationic resins can be effective as capture substances due to theircharge, which has affinity for anchor substrates like cellulose acetate.

When anchor substrates are selected that are intrinsically hydrophilic,there is the risk that they will absorb water from the aqueousenvironment even as they support the oleophilic capture substances thatare absorbing oil. Hence, in embodiments, it is desirable to treathydrophilic anchor substrates with a substance that renders them lesshydrophilic. In embodiments, such treatment can be carried out using asingle oleophilic capture substance: the oleophilic capture substancecan render the anchor substrates hydrophobic while at the same timeallowing the treated anchor substrates to absorb the oil. In otherembodiments, two or more different treatments are required, one that ismore advantageous for rendering the anchor substrates hydrophobic, andone that is more advantageous for attaching an oleophilic capturesubstance to the anchor substrates. In embodiments, the hydrophobictreatment may not increase the oil absorbing capacity of the substrate,but can decrease the water absorbing capacity. This lowered waterabsorbing capacity can enable the material to more selectively absorboil.

3. Attachment Technologies

A number of technologies can effect the attachment or coating of theanchor substrates with the oleophilic capture substance to produceremovable complexes. The selection of attachment technology can dependupon the nature of the capture substance and the nature of the anchorsubstrate. The term “attach” refers to a coupling between entities, herethe capture substance and the anchor substrate. Such a coupling can bedirect, as with a covalent chemical bond being formed between thecapture substance and the anchor substrate, or it can be indirect, wherean intermediary agent (e.g., a bifunctional coupling agent) bonds bothto the anchor substrate and the capture substance. Attachment betweenthe anchor substrate and the capture substance can occur by any feasiblemechanism consistent with an embodiment of the invention. As examples,non-limiting mechanisms by which anchor substrates and capturesubstances can be bound together can include covalent bonding,non-covalent bonding, electrostatic (or ionic) forces, Van der Waalsforces, hydrogen bonding, surface coating, other intermolecular forces,and combinations of the listed mechanisms. Other, mechanical mechanismsfor attaching the capture substances to the anchor substrate includeprecipitation, spray deposition, evaporation, adsorption, layer-by-layerdeposition, and the like.

In an embodiment, to effect attachment of a capture substance to ananchor substrate, a dilute solution of a hydrophobic material can beused. Examples of such hydrophobic materials suitable for capturesubstances include, but are not limited to, naphthenic acid, asphaltene,rubber cement, hydrophobic starch, non-polar polymers (such as olefins,SBR, polyisobutylene, polyisoprene, polybutadiene, styrenics andcopolymers), and chitosan.

In embodiments, chitosan can be attached to anchor substrates by pHtitration: it can be dissolved in water under acidic conditions andexposed to the anchor substrates. As the pH of the chitosan solution isincreased, the chitosan can precipitate out of the solution onto thesurface of the anchor substrates, forming a near-monolayer coating onthe anchor substrates that can act as a capture substance. In otherembodiments, styrene maleimide copolymers can be used as capturesubstances, being attachable to anchor substrates by pH titration. Forstyrene maleimide copolymers, as the pH of the solution increases, theycan precipitate out of the solution, forming a near-monolayer coating onthe anchor substrates that can act as a capture substance.

In other embodiments, a hydrophobic capture substance can be dissolvedin an appropriate solvent (e.g., Isopar, acetone, alcohols, alkanes, orany mixtures thereof, and the like). The substrate material(s) can bedipped in the solution and removed, bearing the capture substance on thesurfaces. Or the solution containing the dissolved capture substance canbe sprayed onto the anchor substrates. Upon drying, the substratesbecome coated with the capture substance. In embodiments, the dryingprocess can be accelerated by heating or vacuum exposure. In otherembodiments, the hydrophobic substance can be applied as a concentratedor solvent-free liquid, in the form of an aerosol or spray application.Solid hydrophobic modifiers can be attached by mixing followed byheating to melt the solid material onto the surface of the substrate. Inembodiments, the substrate material can be treated with capture materialin a continuous process, such as on a continuous ribbon blender, a pugmill, or a conveyor belt.

In embodiments, an anchor substrate can be prepared to capture targetoils, for example, by using sand as an anchor substrate, and attachingto it low levels (about 2.0%) of oleophilic capture substances selectedfrom the group consisting of asphaltene, diluted heavy crude oil,chitosan, chitosan with a glycidyl hexadecyl ether modifier, wax, AegisMicrobe sword compound, lignin-organosolv, styrene butadiene rubber,polyisoprene, styrene/isoprene, styrene maleic acid, SEB/MA,polyisobutylmethacrylate, lauryl acrylate, linseed oil, and the like. Inembodiments, calcium carbonate can be used as an anchor substrate, witha capture substance attached to it that is selected from the groupconsisting of fatty acids, naphthenic acids, and the like. Inembodiments, the capture particles can be in the form cellulose esterfibers such as cellulose acetate can be treated with oleophilic capturesubstances, for example by spraying, by evaporation, or by dissolvingthe hydrophobic substances into the cellulose acetate solution beforeforming the fibers. In other embodiments, the cellulose acetate fiberscan be formed according to standard industrial practices, followed bytreatment with a hydrophobic agent. This hydrophobic agent can be in theform of a solid, powder, emulsion, dispersion, solution, or aerosol.

4. Exemplary Applications

To treat an aqueous surface covered with floating oil, a sufficientlylarge number of capture particles should be brought into contact withthe target oil so that it can be captured and sequestered. For example,a layer of crude oil on the surface of the ocean would be treated withcapture particles to form removable complexes. Depending upon thedensity of the anchor substrates that comprise the capture particles,the removable complexes can float on the surface of the ocean to beskimmed off or scooped up, or the removable complexes can sink to thebottom of the ocean to reside there indefinitely. Density of the anchorsubstrates can be selected to arrange any appropriate destination of theremovable complexes at different ocean depths.

In embodiments, large contaminated areas of water can be treated bydispersing the capture medium in particulate form widely andefficiently, as could be accomplished by aerial sprinkling (like cropdusting) or spraying from planes, helicopters, or surface vessels. Thecapture medium can complex rapidly with the target oil and, withappropriate density, can sink. For heavy crude oil, its high viscositycan assist in this “densifying” or “weighting” process, as the removablecomplexes do not easily detach from the rest of the target oil blobs.Since the density difference between sea water and oil/crude is small tobegin with, a small amount of attachment to or integration with thecapture medium can lead to flipping of the tendency from “float” to“sink” for an entire oil mass, thereby effecting a settling of a largerarea of the oil blob and removing it from the water surface. Sinking theoil blobs through formation of removable complexes can prevent them frombeing carried further by ocean currents, which would otherwise allowthem to contaminate remote areas.

In embodiments, compositions can be prepared that can sequester an oilmass into a floating composite. Such floating compositions can comprisean anchor substrate bearing an oleophilic capture substance, orcompositions can comprise anchor substrates without coatings that arethen mixed with one or more oleophilic capture substances. Contactingthe oil mass with the floating compositions can sequester the oil byabsorbing it onto the anchor substrates, where the anchor substrates aredesigned to float on the surface of the water.

Other technologies can be combined with the use of the capture media tofurther prepare the oil for capture. For example, coalescencetechnologies can be employed to increase the coalescence of thedispersed oil droplets in the aqueous medium, making it easier to attachmasses of target oil to the capture media. In other embodiments,dispersion or emulsion technologies can be used to break up masses oftarget oil so that it can attach more readily to certain target media.Deployment of the capture media can take place following theseadjunctive technologies, or simultaneous therewith. Deployment, as wouldbe understood in the art, involves a variety of mechanisms to bring thecapture medium into contact with the target oil. Deployment mechanismscan include spraying, spreading, stirring, injecting, dumping,broadcasting, spilling, shooting, casting, throwing, and the like, withthe mechanism being selected that is appropriate to the size and shapeof the capture medium and the size, shape, consistency and location ofthe target oil, all as would be appreciated by those of ordinary skillin the art. In embodiments, the capture medium can be prepared beforedeployment. In other embodiments, the capture medium can be formed atthe same time as the deployment. In yet other embodiments, the anchorsubstrate can be deployed first, then combined with the modifiertechnology. In such embodiments, the modifier technology is deployed aswould be appropriate for its physical configuration.

In other embodiments, capture media configured as larger-scale formedarticles such as sheets, booms, networks, fiber masses, geometricobjects or the like can be deployed onto or within a region of targetoil. For example, capture media shaped as a sheet can “blot” up oil froman aqueous surface. As another example, capture media formed intonetworks with fine interstices can be used to filter oil from an aqueousstream or vessel. Capture media formed into fiber masses can offer alarge surface area for the complexation of target oil, so that theentire mass can be removed as a unit. Texturing of the larger-scalesolid anchor substrates can be engineered to increase surface area forcomplexation.

In embodiments, anchor substrates or substrate types useful forsequestering oil into floating composites in accordance with thesesystems and methods can be prepared from organic or inorganic materials.In embodiments, the anchor substrates can have a density of between 0.1and 1.0 g/cc. In other embodiments, anchor substrates can be selectedwith a density that does not lead to the sequestration of target oilinto floating composites, but still yields a mass of removable complexesthat can be separated from the fluid stream by mechanical or otherfamiliar separation techniques, such as skimming, filtration, vacuuming,segregation, or other techniques familiar in the art for removingparticulate matter from fluids.

A variety of natural or synthetic organic materials are suitable asanchor substrates without limitation, with examples as disclosed above.For further exemplification, anchor substrates can include, inembodiments, cellulosic plant matter (such as peat, bagasse, leafparticles, husks, grasses, hay, straw, bark, lignocellulose products,and the like), plant/cereal seed matter (such as rice, corn, soybeans,wheat, barley, oats, sorghum, rye, buckwheat, and the like), plant/nutshells (such as peanuts, walnuts, pecans, and the like), animal matter(such as feathers, scales, fur, hair, and the like), synthetic organicmatter (such as plastic scrap, crumb rubber and the like), or inorganicmatter (such as char, ash, pumice, vermiculite, perlite, attapulgite,zeolite, diatomaceous earth, and the like). Formulations comprisinganchor substrates can include mixtures of different types of anchorsubstrates. The substrates for anchor substrates can be processed,without limitation, by a variety of techniques familiar in the art, suchas drying, grinding, milling, size classification, washing, expanding,and the like.

In embodiments, a fibrous anchor substrate like cellulose acetate can beadvantageously used as an anchor substrate. Fibers, e.g., celluloseacetate, can be constructed into sheets, booms, webs, lattices, or otherarrangements that are suitable, either before or after treatment witholeophilic capture substances as described below. In embodiments,lattice-forming fibers, e.g., cellulose acetate, can be deployed ascontinuous bands or as a fibrous sheet. In embodiments, the celluloseacetate is deployed in a form that is highly expanded, to allow for ahighly lofted, low density, expanded material. Hence, the retrieval ofoil from fluid streams can be simplified: instead of picking upagglomerations of particles, for example, a retrieval system can pull upa continuous ribbon or a fibrous sheet. Fibrous anchor substrates thatare treated with oleophilic capture substances can also be deployed inother suitable arrangements for capturing oil from fluid streams,including pompoms, brooms, mops, and the like. In other embodiments, theanchor substrates treated with oleophilic capture substances can be usedas filler or “stuffing” for other porous containers such as pillows,booms, pads, socks, blankets, and the like that come in contact with oilin aqueous environments. Used in this way, the treated anchor substratescan adsorb the oil while the pillows, booms, etc. act as mechanicalbarriers that confine the oil and thereby facilitate its capture.

Anchor substrates modified with or combined with oleophilic capturesubstances form compositions that can sequester an oil mass. Combiningor modifying an anchor substrate with an oleophilic capture substancecan render an otherwise hydrophilic anchor substrate (e.g., hay,bagasse, and the like) hydrophobic. Thus, the anchor substrate preparedin accordance with these systems and methods can absorb less water thanthe unmodified substance, so that collection of the target oil capturedin the removable complex will be facilitated and waste volume will beminimized due to the low amount of water that is entrapped.

Oleophilic capture substances for use with anchor substrates cancomprise hydrophobic materials that can be coated onto the anchorsubstrates or that can be mixed in with the anchor substrates. One ormore oleophilic capture substances can be used in a composition with oneor more anchor substrates. The oleophilic capture substances can be usedas coatings, used as components of mixtures, or any combination thereof.Oleophilic capture substances can be selected to support the desiredphysical properties of the anchor substrates. For example, oleophiliccapture substances to be used for floating purposes support the buoyantnature of the anchor substrates.

Examples of oleophilic capture substances suitable for use in accordancewith these systems and methods include polymers and copolymers ofstyrene, butadiene, isoprene, acrylate esters, propylene, ethylene, andthe like. Further examples of oleophilic capture substances suitable foruse in accordance with these systems and methods include thermoplasticslike acrylonitrile butadiene styrene, ethylene vinyl acetate,polyacrylonitrile, polyethylene terephthalate, nylon, polyvinylchloride, polyvinyl alcohol, and the like. Yet other examples ofoleophilic capture substances suitable for use in accordance with thesesystems and methods include elastomers like rubber, polyisoprene,polybutadiene, and the like. Further examples of oleophilic capturesubstances suitable use in accordance with these systems and methodsinclude waxes (e.g., paraffin, plant wax, beeswax), resins, tree resins,rosin, sap, vegetable oils, and the like. Additional examples ofoleophilic capture substances suitable for use on accordance with thesesystems and methods include fatty acids, e.g., in the C12-C30 range, forexample, stearic acid, oleic acid, blends of fatty acids, and esters,amides and glycerides thereof, and the like. Yet other examples ofoleophilic capture substances suitable for use in accordance with thesesystems and methods include oils such as crude oil, bitumen, slack wax,mineral oil or asphalt, and the like. Further examples of oleophiliccapture substances suitable for use in accordance with these systems andmethods these purposes include hydrophobic starches. Additional examplesof oleophilic capture substances suitable for use in accordance withthese systems and methods include sizing agents such as alkenylsuccinicacid anhydride, alkylketene dimer, rosin, and the like.

Oleophilic capture substances can be combined with the chosen anchorsubstrate(s) using appropriate processes for producing mixtures, coatedparticles or other compositions, including dry blending or milling, wetblending or milling, coextrusion, spray drying, and the like. Inembodiments, the anchor substrates can be coated with a solution of theoleophilic capture substance, followed by the removal of the solvent,resulting in anchor substrates bearing the oleophilic capture substanceas a coating. In embodiments, the anchor substrates can be coated with aliquid or molten form of the oleophilic capture substance. Inembodiments, the anchor substrates can be exposed to a foamedcomposition of the oleophilic capture substance, so that the capturesubstance comes to reside on the anchor substrates.

In embodiments, compositions in accordance with these systems andmethods can be applied to target oil masses using a variety oftechnologies, as would be appreciated by those of ordinary skill in theart. The compositions can be prepared in loose granular form, suitablefor sprinkling, spraying, or other mass dispersion methods. Thecompositions can be exposed to the target oil masses using aerialdispersion (e.g., crop-dusting) techniques, spraying techniques, mixingtechniques, or can be delivered by pressure, propulsion or explosioninto the fluid stream. The compositions can also be incorporated intoother delivery systems. For example, the floating compositions can besupported or delivered in the form of booms, socks, pads, nets, filters,or other composite materials for which they can comprise the activeingredients.

In other embodiments, compositions in accordance with these systems andmethods can be made using an appropriate anchor substrate, such ascellulose acetate fibers, that has been modified to remove other organicmaterials from a fluid stream. The modified fibers can be formed into asuitable geometry, for example as a filtration product, as a sheet, as aloose collection of fibers, as a slurry, or the like. The organiccontaminants, including but not limited to oily materials, can contactthe modified fiber assemblage for removal. In embodiments, for example,hydrophobically modified anchor substrates (e.g., cellulose acetate) canbe made by coating or modifying the anchor substrates or fibers withhydrophobic polymers, fatty acids, waxes, and the like. Such materialscan be used for removing organic substances from fluid streams,including but not limited to oily materials. For example, water solubleor other organic materials or nutrients imposing biochemical or chemicaloxygen demand on a water stream can be removed using these systems andmethods. Aggregations of modified anchor substrates in accordance withthese systems and methods are suitable for use with a variety of fluidstreams, such as those found in water for hydraulic fracturing, bilgewater, produced water from oil and gas operations, refinery effluents,paint waste, removal of oily mist from gas streams like compressorexhaust, emulsion breaking, coalescing, and the like.

Modified anchor substrates or fibers can be arranged in any suitablegeometric shape, and can be deployed within a device specificallyadapted for removing contaminants from the fluid stream. As an example,cellulose acetate fibers modified in accordance with these systems andmethods can be arranged as a component of a flow through filtercartridge for removing hydrophobic organic contaminants from a fluidstream. The filter cartridge containing the removed organic components,sequestered by the removable complexes with the anchor substrates, canbe disposed of by incineration, for example.

In embodiments, removable complexes as described herein can be furtherprocessed following their removal. For example, the removable complexescan be processed to allow the separation of the oil contained thereinfrom the capture medium. In embodiments, the capture medium can bereused following the release of the entrapped oil, while in otherembodiments, the capture medium is disposed of. In embodiments, theremovable complexes as described herein can be incinerated to destroythe remaining oily substance.

EXAMPLES Example 1 Sand-Silane Modification

A modified sand capture particle was prepared using 20 gms of sand(white quartz, Aldrich, 50-70 mesh) as the anchor substrate combinedwith 20 gms of a 6.9% Silane 9-6346 solution as the oleophilic coating.To prepare the Silane solution, Dow Corning Silane 9-6346 (72% inmethanol) was dissolved in a 95:5 mixture by volume of ethanol withwater. The pH was adjusted to 5.41 with acetic acid. The solution wascontinuously stirred at room temperature for one hour. Afterpreparation, 20 gms of sand was added to 20 gms of the Silane solutionand soaked for 30 minutes, with the solvent then rotary-evaporated toproduce modified sand capture particles. The modified sand was cured inan oven at 110° C. for 15 minutes. The cured sand was rinsed withdeionized water three times and filtered through 45 micron size filterpaper. The modified sand was then dried at 110° C. for one hour.

Example 2 Sand Modified with Poly(Styrene Ethylene Butylene)

A polymer solution of poly(styrene ethylene butylene) was prepared bydissolving 0.2 gm of the polymer (Kraton) in 20 ml toluene. 20 gms ofsand (white quartz, Aldrich, 50-70 mesh) were used as the anchorsubstrate. The sand was combined with the polymer solution and mixed for10 minutes. The solvent was removed by rotary-evaporation.

Example 3 Sand Modified with Organosolv Lignin

A solution of organosolv lignin was prepared by dissolving 0.4 gm oforganosolv lignin (Aldrich) in 20 ml acetone. 20 gms of sand (whitequartz, Aldrich, 50-70 mesh) were used as the anchor substrate. The sandwas combined with the organosolv lignin solution and mixed for 10minutes. The solvent was removed by rotary-evaporation.

Example 4 Sand Modified with Paraffin Wax

A solution of paraffin wax was prepared by dissolving 0.4 gm of paraffin(Aldrich, melting point 65° C.) in 20 ml heptane. 20 gms of sand (whitequartz, Aldrich, 50-70 mesh) were used as the anchor substrate. The sandwas combined with the paraffin solution and mixed for 10 minutes. Thesolvent was removed by rotary-evaporation.

Example 5 Sand Modified with Chitosan

0.6 gm of acetic acid and 100 gm of water were combined in a beaker. 0.5gm of chitosan (Chitoclear cg 800, Primex, Iceland) was added to thesolution and stirred until it dissolved. 5 gm of sand (white quartz,Aldrich, 50-70 mesh) was added to the chitosan solution. This mixturewas stirred, and the pH was slowly increased to ˜pH8 by adding 5M NaOH.The precipitated solid was filtered by gravity, washed with deionizedwater, and dried under a vacuum at 70° C. for one hour.

Example 6 Deposition of Asphaltene on Sand

20 g of Sand (white quartz, Aldrich, 50-70 mesh) was mixed with 70 g ofheavy oil (API=10, Viscosity=40,000 cps at RT). The mixture was heatedat 80° C. for 15 minutes while stirring. To this mixture was addedapproximately 650 ml of heptane. Next the solid was separated by gravityfiltration, washed 3 times with 20 ml of heptane and dried under vacuumat 70° C. for 1 hour.

Example 7 Deposition of Crude Oil on Sand

A solution of heavy crude oil (API=10, Viscosity=40,000 cps at roomtemperature) in toluene was prepared by dissolving 2 g of the heavy oilin 70 g of toluene. 0.76 g of this solution was weighted and furtherdiluted by adding 20 ml of toluene. Next, 10 g of sand (white quartz,Aldrich, 50-70 mesh) was added to the solution. The solvent wasevaporated by rotary-evaporation and the obtained solid was dried undervacuum at 70° C. for 1 hour.

Example 8 Deposition of Oleic Acid on Calcium Carbonate

0.2 gm of oleic acid (Aldrich) was dissolved in approximately 35 ml oftoluene. To this solution was added 10 g of Precipitated CalciumCarbonate (Specialty Materials, Bethlehem Pa.). The mixture was shakenvigorously in an orbital mixer for 15 minutes. Next the solvent wasevaporated by rotary-evaporation and the obtained solid was dried undervacuum at 70° C. for 1 hour.

Example 9 Deposition of Naphthenic Acid on Calcium Carbonate

15 gm of naphthenic acids (Aldrich, acid number 230) was added to 400 mlIsopar M (Exxon Mobile) in a 500 ml Nalgene bottle. Next, 25 g ofprecipitated calcium carbonate was added and the whole mixture wasagitated in an orbital shaker (200 rpm) overnight. The sample wascentrifuged at 1,500 rpm for 5 minutes to separate the solid fromliquid. The solid was dried under vacuum at 70° C. for 1 hour.

Example 10 Preparation of Synthetic Seawater Solution

Microprocessed scientific grade marine salt mix (Coralife, FranklinWis.) was used to prepare 5 gallons of synthetic seawater by followingthe instructions provided by the manufacturer (i.e., mixing sea salt inan appropriate amount of tap water (about ½ cup sea salt per gallonwater), then obtaining the appropriate amount of salinity by adjustingsolution strength to a specific gravity of 1.022 g/cc using ahydrometer).

Example 11 Oil Clean-Up Test

10 ml of synthetic seawater prepared in accordance with Example 10 and0.11 ml crude oil (API 37) were mixed in a 20 ml. scintillation vial.The oil was then allowed to form a film on the surface of the watersample. 0.4 gm. of a sand sample were added to the sea water/oilsolution and agitated for 5 seconds. The vial was then left to settle.Sand samples modified in accordance with Examples 1, 4, 5, 6, and 7 wereused as test samples, and unmodified sand (white quartz, Aldrich, 50-70mesh) was used as the control. Untreated sand trapped some oil dropletswhen settling to the bottom. Modified sand absorbed more oil beforesettling out. When compared to the control test using the unmodifiedsand, the use of modified sand removed more oil from the sample.

Example 12 Microscopy of the Settled Sand Bed

The sand beds produced by the experiments of Example 11 were observedunder the microscope at 50× magnification. The sand beds using theunmodified sand showed some trapping of oil droplets. The sand bedsusing the unmodified sand showed large agglomerates of sand surroundedwith an oil coating.

Example 13 Preparation of Floating Composition

A blend of bagasse, stearic acid, and paraffin wax (50:25:25 ratio) wasprepared and this was ground up using a blender. This composition iscapable of floating on an aqueous surface.

Example 14 Preparation of Floating Composition

A blend of bagasse, stearic acid, and paraffin wax (20:40:40 ratio) wasprepared and this was ground up using a blender. This composition iscapable of floating on an aqueous surface.

Example 15 Preparation of Floating Composition

A blend of bagasse and bitumen (80:20 ratio) was prepared by mixing.This composition is capable of floating on an aqueous surface.

Example 16 Preparation of Floating Composition

A blend of bagasse and paraffin wax (80:20 ratio) was prepared byheating these materials above the melting point of the wax (65° C.) andthen mixing them together.

Example 17 Formation of Floating Removable Complex with Crude Oil

Synthetic seawater prepared in accordance with Example 10 was placed ina 1 liter beaker with stir bar at room temperature and 3 grams of crudeoil (30 API gravity) were added, forming a layer of oil on the aqueoussurface. 3 gm of the composition prepared in accordance with Example 13was added to the oil layer. It was observed to absorb the oil into asolidified floating mass. The mass was removed from the surface of thewater by mechanical screening methods. For comparison, a sample of crudeoil without the additive could not be removed from the water surfaceusing mechanical screening. This test demonstrated the formation of afloating removable complex that could be readily collected. In otherexamples, the removable complex can be captured by other mechanicalmeans, for example by a raking action.

Example 18 Formation of Removable Complex with Crude Oil

Synthetic seawater prepared in accordance with Example 10 was placed ina 1 liter beaker with stir bar at room temperature and 3 grams of crudeoil (30 API gravity) were added, forming a layer of oil on the aqueoussurface. 3 gm of the composition prepared in accordance with Example 14was added to the oil layer. It was observed to absorb the oil into asolidified floating mass. The mass was removed from the surface of thewater by mechanical screening methods. For comparison, a sample of crudeoil without the additive could not be removed from the water surfaceusing mechanical screening. This test demonstrated the formation of afloating removable complex that could be readily collected. In otherexamples, the removable complex can be captured by other mechanicalmeans, for example by a raking action.

Example 19 Comparison of Treated and Untreated Bagasse

The wax/bagasse blend of Example 16 was added to the synthetic seawaterprepared in accordance with Example 10. There was no evidence of wettingfor this substance, indicating that the wax/bagasse blend washydrophobic. In a comparative experiment, unmodified bagasse fibers wereadded to the synthetic seawater preparation, and they became wetted inless than 5 minutes, indicating that the untreated fibers arehydrophilic.

Example 20 Preparation of a Floating Composition

A blend of bagasse, stearic acid, and paraffin wax can be prepared in a90:5:5 ratio. This blend can be ground up using a blender.

Example 21 Preparation of a Floating Composition

A blend of bagasse and stearic acid can be prepared in a 95:5 ratio.This blend can be ground up using a blender.

Example 22 Preparation of a Floating Composition

Bagasse can be treated with an aqueous emulsion of wax in a 90:10 ratioof bagasse to wax. This mixture can be dried to form a coated product.

Example 23 Preparation of a Floating Composition

Dried hay can be treated with a liquid fatty acid mixture in a 80:20ratio.

Example 24 Preparation of a Floating Composition

Sawdust can be treated with a solution of paraffin wax in volatileorganic solvent. After evaporation of the solvent, the ratio of sawdustto wax can be 90:10.

Example 25 Preparation of a Floating Composition

Feathers can be treated with EVA polymer in liquid emulsion form. Themixture, once dried, would be ready to use for the formation of aremovable complex with a target oil.

Example 26 Formation of Removable Complex with Crude Oil

Synthetic seawater prepared in accordance with Example 10 can be placedin a 1 liter beaker with stir bar at room temperature, and 3 grams ofcrude oil (20 API gravity) can be added, forming a layer of oil on theaqueous surface. 3 gm of the composition prepared in accordance withExample 13 can be added to the oil layer to absorb the oil into asolidified floating mass. This crude oil is a simulation of partiallyevaporated crude oil. The complex formed with the target crude oil canbe removed from the surface of the water by mechanical screeningmethods. For comparison, a sample of crude oil without the additivewould not be removed from the water surface using mechanical screening.

Example 27 Formation of a Removable Complex with Crude Oil

Synthetic seawater prepared in accordance with Example 10 can be placedin a 1 liter beaker at room temperature, and 3 grams of crude oil (30API gravity) can be added. With intense mixing, the crude oil can beemulsified in the water, and the emulsion layer can float on the surfaceof the seawater. 3 gm of the composition prepared in accordance withExample 14 can be added to the oil layer, with the absorption of the oilinto a solidified floating mass. The mass can be removed from thesurface of the water by mechanical screening methods. For comparison, asample of emulsified crude oil without the additive would not beremovable from the water surface using mechanical screening.

Example 28 Preparation of Cellulose Acetate Substrate

Cellulose acetate fibers were obtained from “Filter Tips” (manufacturedby TOP Tobacco L.P., Spain) by removing the paper that surrounded thefibrous filters and grinding the filter fibers in a blender for about 1minute.

Example 29 Coating Cellulose Acetate Fibers with Oil (Samples AM1, AM2,and AM3)

Samples of oil-coated cellulose acetate fibers were prepared by usingthree different oils as coatings: Sample AM1 used a cooking gradevegetable oil coating from Shaw's Supermarket, Sample AM2 used a mediumgrade crude oil coating, and Sample AM3 used a mineral oil from CVSDrugstore. To prepare each oil-coated cellulose acetate fiber sample,0.025 gm of the oil for coating was dissolved in 50 ml. of hexane; 2.5gm of cellulose acetate fibers prepared in accordance with Example 28were added to this solution and the mixture was stirred manually for 5minutes. The solvent was then evaporated in the rotary evaporator, andthe obtained solid was dried under vacuum at 70° C.

Example 30 Coating Cellulose Acetate Fibers with polyDADMAC and StearicAcid (Sample AM4)

3 gm of cellulose acetate fibers prepared in accordance with Example 28were added to a solution of 0.45 g of a 20 wt % water solution ofpoly(diallyldimethylammonium chloride) (polyDADMAC, Aldrich), 15 g ofDI-water and 35 ml of isopropanol (Aldrich). After the mixture wasstirred manually for 5 minutes, an additional 40 ml of isopropanol wasadded, and the mixture was stirred for another 5 minutes. In a separatebeaker, a solution was prepared that included 0.475 gm of stearic acid(JT Baker) dissolved in 20 gm of water containing 0.33 gm of NaOH 5M and20 ml. isopropanol. The cellulose acetate fiber mixture was added tothis solution while stirring vigorously. The liquid was then filteredoff by gravity and the fibers were dried under vacuum at 70° C.

Example 31 Coating Cellulose Acetate Fibers with polyDADMAC, StearicAcid, Mineral Oil (Sample AM5)

3 gm of cellulose acetate fibers prepared in accordance with Example 28were added to a solution of 0.45 g of a 20 wt % water solution ofpolyDADMAC, 15 g of DI-water and 35 ml of isopropanol (Aldrich). Afterthe mixture was stirred manually for 5 minutes, an additional 40 ml ofisopropanol was added, and the mixture was stirred for another 5minutes. In a separate beaker, a solution was prepared that included0.475 gm of stearic acid (JT Baker) dissolved in 20 gm of watercontaining 0.33 gm of NaOH 5M, 20 ml. isopropanol, and 0.3 gm mineraloil (from CVS Drugstore). The cellulose acetate fiber mixture was addedto this solution while stirring vigorously. The liquid was then filteredoff by gravity and the fibers were dried under vacuum at 70° C.

Example 32 Coating Cellulose Acetate Fibers with polyDADMAC, StearicAcid and Benzoic Acid (Sample AM6)

3 gm of cellulose acetate fibers prepared in accordance with Example 28were added to a solution of 0.45 g of a 20 wt % water solution ofpolyDADMAC, 15 g of DI-water and 35 ml of isopropanol (Aldrich). Afterthe mixture was stirred manually for 5 minutes, an additional 40 ml ofisopropanol was added, and the mixture was stirred for another 5minutes. In a separate beaker, a solution was prepared that included0.2375 gm of stearic acid (JT Baker) dissolved in 20 gm of watercontaining 0.33 gm of NaOH 5M, 20 ml. isopropanol, and 0.102 gm benzoicacid (Aldrich). The cellulose acetate fiber mixture was added to thissolution while stirring vigorously. The liquid was then filtered off bygravity and the fibers were dried under vacuum at 70° C.

Example 33 Coating Cellulose Acetate Fibers with Stearic Acid (SampleAM7)

0.475 g of stearic acid was dissolved in 20 g of DI-water containing0.33 g of NaOH (5 M) and 20 ml of isopropanol. 3 g of the celluloseacetate fibers prepared in accordance with Example 28 were added to thesolution and the whole mixture was stirred manually for 5 minutes. A fewdrops of HCL (37 wt %) were added to the mixture to decrease its pH toapproximately 2. Next the liquid was filtered off by gravity and thefibers were dried under vacuum at 70° C.

Example 34 Preparing Polyethylene-Coated Cellulose Acetate Fiber Bundles(Sample AM8)

Cellulose acetate fiber bundles were prepared from cigarette filters(“Filter Tips” manufactured by TOP Tobacco L.P., Spain) by removing thepaper that surrounded the fibrous filters and cutting the tips into 3-4mm long small cylindrical-shaped bundles having an 8 mm diameter. 2.6 gmcut filter bundles were dipped into 10% Michem Emulsion 39235 (highdensity polyethylene emulsion, from Michelman). Excess liquid wasdecanted. The add-on weight of Michem Emulsion 39235 to the dry weightof filter bundles was 81%. Samples were dried in 130° C. convection ovenuntil no further weight changes were recorded.

Example 35 Preparing Wax-Coated Cellulose Acetate Fiber Bundles (SampleAM9)

Cellulose acetate fiber bundles were prepared from cigarette filters(“Filter Tips” manufactured by TOP Tobacco L.P., Spain) by removing thepaper that surrounded the fibrous filters and cutting the tips into 3-4mm long small cylindrical-shaped bundles having an 8 mm diameter. 2.6 gmof the cut filter bundles were dipped into HydraBan 708 (scale waxemulsion, from Michelman). Excess liquid was decanted. The add-on weightof HydraBan 708 to the dry weight of the filter bundles was 86%. Sampleswere dried in 130° C. convection oven until no further weight changeswere recorded.

Example 36 Preparation of Stearic Acid-Coated Cellulose Acetate Fibers(Sample AM10)

Cellulose acetate fiber bundles were prepared from cigarette filters(“Filter Tips” manufactured by TOP Tobacco L.P., Spain) by removing thepaper that surrounded the fibrous filters and cutting the tips into 3-4mm long small cylindrical-shaped bundles having a 8 mm diameter. 2.6 gmof the cut filter bundles were dipped into a solution of 1 gm stearicacid (Aldrich) dissolved in 20 gm ethanol. All the liquid was absorbedby the fiber bundles. Samples were dried in 80° C. convection oven untilno further weight changes were recorded. The sample was then ground in afood processor to form loose fibers.

Example 37 Preparation of Wax-Coated Cellulose Acetate Fibers (SamplesAM11 and AM12)

Cellulose acetate fibers were prepared in accordance with Example 28.2.6 gms of the fibers were dipped into 5% HydraBan 708 and excess liquidwas squeezed off. For one set of samples (AM11), the add-on weight ofHydraBan 708 on cigarette filter was 15%. For another set of samples(AM12), the add-on weight of HydraBan 708 was 35%. The samples weredried at 105-110° C. in the oven until no further weight changes wererecorded.

Example 38 Preparation of Stearic Acid-Coated Cellulose Acetate Fibers(Sample AM 13)

Cellulose acetate fibers were prepared in accordance with Example 28. Asolution was prepared by dissolving 0.31 gm of stearic acid in 15 gms ofethanol. 2.6 gms of the fibers were dipped into this solution and excessliquid was squeezed off. The add-on weight of stearic acid on the fiberbundles was 7%. The samples were vacuum-dried at 80° C. until no furtherweight changes were recorded.

Example 39 Preparation of Silane-Coated Cellulose Acetate Fibers (SampleAM14)

Cellulose acetate fibers were prepared in accordance with Example 28. Asolution was prepared by dissolving 0.31 gm of Dow Corning 9-6346(quaternary reactive silane) in 16 gms of 95:5 ethanol/water solution.2.6 gm of the fibers were dipped into this solution and the excessliquid was squeezed off. The add-on weight of the DC 9-6346 silane onthe fiber bundles was 4.5%. The samples were vacuum-dried at 80° C.until no further weight changes were recorded.

Example 40 Polypropylene Fibers (Sample AM15)

Polypropylene rope (¼inch diameter, yellow pigmented, 212 lbs work load,T.W. Evans Cordage Co., Inc.) was untwisted and cut into 10 mm lengthindividual fibers.

Example 41 Coating of Cellulose Acetate Fibers with Styrene MaleimideCopolymer (Sample AM16)

A 1% solution of Styrene Maleimide copolymer (SMA 30001 form CrayValley, France) in water was prepared by stirring 0.5 g of the SMA 30001in 50 ml of water containing 0.5 g of HC137%. 3 g of the previoussolution was diluted with 20 ml of DI-water. Next 3 g of the celluloseacetate fibers prepared in accordance with Example 26 was added to thesolution. The pH of the solution was increased to approximately 8 byadding NaOH 5M while stirring the mixture. The liquid was filtered offby gravity and the fibers were dried under vacuum at 70° C.

Example 42 Oil Absorbance Test

A sample of an absorbent material prepared in accordance with Examples29-41 (AM1-AM16), each sample weighing about 2 gm, was placed in a wiremesh basket, weighed and immersed in a one-inch thick layer of mediumcrude oil. After 15 minutes of exposure, the basket was lifted from theoil bath and allowed to drip for about 30 seconds while being lightlyshaken. The sample and the basket were then weighed. The differencebetween this weight and the initial weight corresponded to the amount ofoil absorbed. A correction factor of 0.6 gms was subtracted from thefinal mass to account for oil adhering to the basket, yielding thecorrected mass for each oil-exposed sample. The oil absorbance value foreach sample was calculated by dividing the corrected mass by the drymass.

Example 43 Water Absorbance Test

A sample of an absorbent material prepared in accordance with Examples29-41 (AM1-AM16), each sample weighing about 0.75 gm, was placed in aplastic 500 ml bottle containing 250 ml of water. The bottle was placedhorizontally on a shaker table for 15 minutes. After 15 minutes ofexposure, the bottle was removed from the shaker table and the contentspoured through a filter. The sample was removed from the filter, allowedto drop for approximately 30 seconds, and then weighed. The mass ofwater absorbed by the sample was calculated by subtracting the mass ofthe dry sample from the mass of the wet sample. The water absorbancevalue for each sample was calculated by dividing the mass of the wetsample by the mass of the dry sample.

Example 44 Comparing Oil Absorbance Values to Water Absorbance Values

For each of the samples prepared in accordance with Examples 29-41, theoil absorbance value and the water absorbance value was determined, asshown in Table 1. The oil absorbance value for each sample was plottedagainst the water absorbance value, as shown on Graph 1 in the FIGURE.Table 1 and the FIGURE also show that the values for the experimentalsamples (prepared in accordance with Examples 29-41) can be compared tothe oil absorbance and water absorbance values for the controls(unmodified Filter Tips and unmodified cellulose acetate fiber bundles(Eastman)), and for one commercially available product (MOP® Maximum OilPickup, MOP Environmental Solutions, Inc.). Advantageously, an absorbentmaterial displays a high oil absorbance value while minimizing theamount of water absorption.

TABLE 1 Absorbent Material Water Oil Example Number DescriptionAbsorbance Absorbance 29 AM1 Cellulose Acetate (fibrous strands) coatedin 14.64 18.13 vegetable oil 29 AM2 Cellulose Acetate (fibrous strands)coated in 16.24 20.9 crude oil 29 AM3 Cellulose Acetate (fibrousstrands) coated in 19.34 N/A mineral oil 30 AM4 Cellulose Acetate(fibrous strands) coated in 13.71 25 polyDADMAC and stearic acid 31 AM5Cellulose Acetate (fibrous strands) coated with 11.44 13.44 polyDADMACfollowed by stearic acid and mineral oil 32 AM6 Cellulose Acetate(fibrous strands) coated with 12.60 15.58 polyDADMAC followed by stearicacid/benzoic acid 33 AM7 Cellulose Acetate (fibrous strands) coated with11.85 15.32 stearic acid 34 AM8 Cellulose Acetate (small cylindricalshaped 5.74 5.28 particles) coated with polyethylene 35 AM9 CelluloseAcetate (small cylindrical shaped 5.94 4.8 particles) coated withHydroban 708 36 AM10 Cellulose Acetate (small cylindrical shaped 11.0015.6 particles) coated with stearic acid and then blended into fibrousstrands 37 AM11 Cellulose Acetate (fibrous strands) coated with 8.939.93 Hydroban 708 37 AM12 Cellulose Acetate (fibrous strands) coatedwith 8.56 10.18 Hydroban 708 38 AM13 Cellulose Acetate (fibrous strands)coated with 9.24 9.68 stearic acid 39 AM14 Quaternary alkylcyline 12.7410.59 40 AM15 Chopped up polypropylene strands 0.52 2.8 41 AM16Cellulose acetate (fibrous strands) coated with 13.92 21.73 SMA-Icontrol MOP 201 Commercial product 5.13 9.36 control Top Filter TipsCellulose Acetate (fibrous strands) 23.43 23.46

Example 45 Preparation of PDAC Modified Substrate

A 0.1% solution of modifier was made by diluting a 20% solution ofpoly(diallyldimethylammonium chloride) (PDAC, from Aldrich Chemical)with water. Then 6.8 g of cellulose acetate was suspended in 1 liter ofthe 0.1% PDAC solution for 10 minutes while stirring the suspension. Theexcess PDAC solution was then drained and the substrate was dried at100° C. for 30 minutes.

Example 46 Preparation of Chitosan Modified Substrate

A 0.1% solution was made by dissolving Chitosan CG800 (from Primex,Iceland) in acidic water (pH˜3.0) overnight while stirring. Then 20 g ofcellulose acetate was suspended in 1 liter of the 0.1% chitosan solutionand pH was raised to ˜8 while stirring to enable chitosan deposition onthe substrate. The solution was then drained and the substrate dried at100° C. for 30 minutes.

Example 47 Preparation of Zein Modified Substrate

A 0.1% solution was made by diluting a 14% solution of Aquazein (FreemanIndustries) in basic water (pH˜10). Then 20 g of cellulose acetate wassuspended in 1 liter of the 0.1% Zein solution and pH was lowered to ˜5while stirring to enable Zein precipitation on the substrate. Thesolution was then drained and the substrate dried at 100° C. for 30minutes.

Example 48 Preparation of Stearic Acid Modified Substrate

In a round bottom flask, 2.540 g stearic acid was dissolved in about 100mL of ethanol. 9.583 g cellulose acetate (from Eastman Chemical) wasadded, and the mixture was shaken for 2 minutes. The ethanol wasevaporated off with a rotary evaporator at 60° C.

Example 49 Preparation of Emulsion

A 0.01 wt % DDBSA (dodecylbenzenesulfonic acid, sodium salt) solutionwas prepared by dissolving DDBSA into water. Then, Isopar M (Exxon) wasadded to the solution until it was approximately 0.1 wt %. This mixturewas then sheared in a Silverson L4RT-A homogenizer at 5500 RPM for 5minutes. Foam was allowed to settle to the top before the emulsion wasused.

Example 50 Calibration Curve for Oil Concentration Measurement

A calibration curve relating nephelometric turbidity to oilconcentration was created using an emulsion of Example 49. The emulsionwas diluted to various concentrations with distilled water ranging from0% dilution to 99% dilution, and the resulting turbidities were measuredwith a Hach 2100P Turbidimeter. The calibration showed a linearrelationship between turbidity and oil concentration.

Example 51 Set-Up of Gravity Feed Column

A preparative chromatography column of 1-1.5 inches in diameter and150-200 mL in volume was filled with 50-80 mL of modified substrate of(examples 45-48). A beaker was placed under the column to catch liquidpassing through the column. The column was then filled with water withthe stopcock closed to allow the substrate to soak in water for 16-24hours.

Example 52 Set-Up of Pump-Assisted Column

A flow-through glass column fitted with Ace-Thred end caps, having ˜90mL volume, was filled completely with ˜16.5 g of modified substrate ofExamples 45-48. The column was fitted vertically, with ⅜″ OD (outerdiameter) flexible tube leaving the top and heading to a beaker, andwith ⅜″ OD flexible tube leaving the bottom going to a three-way valve.The three way valve, each connection being ⅜″ OD flexible tube, wasplumbed such that fluid entering it could be directed either to thebottom of the column or to a drain. This three-way valve was fed by aChem-Tech CTPD-2HS1 peristaltic pump set at 10% of its maximum speed.The peristaltic pump drew from a bucket of emulsion of Example 49 thatwas continuously mixed with a 2-MD-SC Little Giant centrifugal pump.

Example 53 Gravity Feed Oil Removal Test

A column as described in Example 51 was prepared using 13 g of a sampleof stearic acid modified cellulose acetate of Example 48 occupying 60 mLin the column. All excess water was removed by opening the stopcock anddraining the column. An emulsion of Example 49 was prepared. 100 mL ofthe emulsion was poured into the top of the column, and the stopcock wasused to set the initial flow rate to 9 mL/min. The flow rate wasmeasured by measuring the mass of the fluid exiting the column over15-30 seconds. The fluid leaving the column was collected periodicallyto measure its turbidity with the Hach 2100P Turbidimeter. The fluidentering the column had a turbidity of 370 NTU and the fluid leaving thecolumn had a turbidity of 8 NTU, representing approximately 98% removalof oil.

Example 54 Gravity Feed Oil Removal Test

A column as described in Example 51 was prepared using 6.5 g of a sampleof PDAC modified cellulose acetate of Example 45 occupying 69 mL in thecolumn. All excess water was removed by opening the stopcock anddraining the column. An emulsion of Example 49 was prepared. 100 mL ofthe emulsion was poured into the top of the column, and the stopcock wasused to set the initial flow rate to 18 mL/min. The flow rate wasmeasured by measuring the mass of the fluid exiting the column over15-30 seconds. The fluid leaving the column was collected periodicallyto measure its turbidity with the Hach 2100P Turbidimeter. The fluidentering the column had a turbidity of 370 NTU and the fluid leaving thecolumn had a turbidity of 27 NTU, representing the removal ofapproximately 93% of oil.

Example 55 Gravity Feed Oil Removal Test

A column as described in Example 51 was prepared using 6.2 g of a sampleof Zein-modified cellulose acetate of Example 47 occupying 45 mL in thecolumn. All excess water was removed by opening the stopcock anddraining the column. An emulsion of Example 49 was prepared. 100 mL ofthe emulsion was poured into the top of the column, and the stopcock wasused to set the initial flow rate to 3 mL/min. The flow rate wasmeasured by measuring the mass of the fluid exiting the column over15-30 seconds. The fluid leaving the column was collected periodicallyto measure its turbidity with the Hach 2100P Turbidimeter. The fluidentering the column had a turbidity of 950 NTU and the fluid leaving thecolumn had a turbidity of 80 NTU, representing the removal ofapproximately 92% of oil.

Example 56 Gravity Feed Oil Removal Test

A column as described in Example 51 was prepared using 6.5 g of a sampleof chitosan-modified cellulose acetate of Example 46 occupying 66 mL inthe column. All excess water was removed by opening the stopcock anddraining the column. An emulsion of Example 49 was prepared. 100 mL ofthe emulsion was poured into the top of the column, and the stopcock wasused to set the initial flow rate to 5 mL/min. The flow rate wasmeasured by measuring the mass of the fluid exiting the column over15-30 seconds. The fluid leaving the column was collected periodicallyto measure its turbidity with the Hach 2100P Turbidimeter. The fluidentering the column had a turbidity of 950 NTU and the fluid leaving thecolumn had a turbidity of 150 NTU, representing the removal ofapproximately 84% of oil.

Example 57 Gravity Feed Oil Removal Test

A column as described in Example 51 was prepared using 6.3 g of a sampleof unmodified cellulose acetate occupying 64 mL in the column. Allexcess water was removed by opening the stopcock and draining thecolumn. An emulsion of Example 49 was prepared. 100 mL of the emulsionwas poured into the top of the column, and the stopcock was used to setthe initial flow rate to 5 mL/min. The flow rate was measured bymeasuring the mass of the fluid exiting the column over 15-30 seconds.The fluid leaving the column was collected periodically to measure itsturbidity with the Hach 2100P Turbidimeter. The fluid entering thecolumn had a turbidity of 950 NTU and the fluid leaving the column had aturbidity of 380 NTU, representing the removal of approximately 60% ofoil.

Table 2 below shows the results of Examples 53-57. As this table showsthe modified fibers are more effective than the unmodified fibers atremoving oil from water.

TABLE 2 Example Modifier used % Removal of Oil 53 Stearic acid 98 54pDAC 93 55 Zein 92 56 Chitosan 84 57 (none) 60

Example 58 Pump Assisted Column Test

A system of Example 52 was set up using a sample of Example 48. The pumpwas turned on to pump the emulsion of Example 49 through the sample inthe column at 14.6 g/min. Samples of the water entering the column(which were obtained from the drain port) and leaving the column weretested for turbidity to obtain Isopar concentration by the calibrationof Example 50. Initially, the column reduced the about of emulsifiedIsopar in the water by 90-95%. After 60 g of Isopar had been removedfrom the emulsion (64 g had been detected entering the column and 4 gleaving), the concentration of Isopar passing the column began to rise.After a total of 93 g of Isopar had entered the column, the sample wasremoved and squeezed between two watch glasses to yield 17.5 g ofmaterial. Allowing the fluid to separate, one could see that about onethird of this material was clear Isopar on the top layer, or about 6 g.This means that the remaining oil was removed from the emulsion bycoalescing. Table 3 below shows the Isopar removal as function of time.

TABLE 3 Total Mass Inlet Isopar Cumulative Outlet Isopar Cumulative %Isopar Flowed Concentration Oil Entered Concentration Oil Exited removedfrom (g) wt % (g) wt % (g) emulsion % 234 1.0% 2.6 0.025% 0.1 98% 7010.73%  6.4 0.010% 0.2 99% 1533 0.59%  11.9 0.068% 0.8 88% 1767 1.0% 14.40.050% 1.0 95% 4234 0.80%  41.5 0.074% 2.9 91% 5183 1.2% 53.3 0.042% 3.397% 5971 1.3% 63.5 0.088% 3.9 93% 6585 1.2% 71.0  0.19% 5.2 84% 67741.1% 73.2  0.27% 5.8 76% 7008 1.3% 76.3  0.30% 6.4 78% 7227 1.2% 79.1 0.36% 7.1 71% 8424 1.0% 92.6  0.46% 13.1 54%

Example 59

A bowl of 150 g of Isopar M was placed on a balance. A 6.8 g sample ofmodified cellulose acetate of Example 48 was placed into the Isopar.After being totally immersed in the Isopar for about a minute, thesample was removed with tweezers and held above the bowl as it drained.When the rate of Isopar dripping from the modified cellulose acetatereached approximately 1 drop per second, the modified cellulose acetatewas transferred to a beaker, and the loss in mass of the bowl of Isoparwas reported as the Isopar absorbed by the modified cellulose acetate.The modified cellulose acetate was then pressed between two watchglasses or glass plates, and the liberated liquid was dropped into thebeaker. The mass of the liquid liberated represented the Isopar thatcould be recovered by squeezing the modified cellulose acetate. Thesqueezed sample was returned to the bowl for another cycle of squeezingfor 5 repetitions. The sample was found to absorb 19 g of Isopar wheninitially dry. Squeezing the saturated sample yielded about 6.5 g ofIsopar. After squeezing, the sample was able to reabsorb about 6.5 g ofIsopar.

Example 60

A bowl of 150 g of Isopar M was placed on a balance. A 6.4 g sample ofunmodified cellulose acetate was placed into the Isopar. After beingtotally immersed in the Isopar for about a minute, the sample wasremoved with tweezers and held above the bowl as it drained. When therate of Isopar dripping from the cellulose acetate reached approximately1 drop per second, the cellulose acetate was transferred to a beaker,and the loss in mass of the bowl of Isopar was reported as the Isoparabsorbed by the cellulose acetate. The cellulose acetate was thenpressed between two watch glasses or glass plates, and the liberatedliquid was dropped into the beaker. The mass of the liquid liberatedrepresented the Isopar that could be recovered by squeezing thecellulose acetate. The squeezed sample was returned to the bowl foranother cycle of squeezing for 5 repetitions. The sample was found toabsorb 25 g of Isopar when initially dry. Squeezing the saturated sampleyielded about 7.5 g of Isopar. After squeezing, the sample was able toreabsorb about 7.5 g of Isopar.

Example 61

A bowl of 200 g of Isopar M was placed on a balance. A 6.1 g sample ofmodified cellulose acetate of Example 48 was wetted with water, squeezedbetween two watch glasses, and then placed into the Isopar. After beingtotally immersed in the Isopar for about a minute, the sample wasremoved with tweezers and held above the bowl as it drained. When therate of Isopar dripping from the modified cellulose acetate reachedapproximately 1 drop per second, the modified cellulose acetate wastransferred to a beaker, and the loss in mass of the bowl of Isopar wasreported as the Isopar absorbed by the modified cellulose acetate. Themodified cellulose acetate was then pressed between two watch glasses orglass plates, and the liberated liquid was dropped into the beaker. Themass of the liquid liberated represented the Isopar that could berecovered by squeezing the modified cellulose acetate. The squeezedsample was returned to the bowl for another cycle of squeezing for 5repetitions. The sample was found to absorb 7.4 g of Isopar whenpre-wetted with water. Squeezing the saturated sample yielded about 4.3g of material. After squeezing, the sample was able to reabsorb about4.2 g of Isopar.

Example 62

A bowl of 200 g of Isopar M was placed on a balance. A 5.2 g sample ofunmodified cellulose acetate was wetted with water, squeezed between twowatch glasses, and then placed into the Isopar. After being totallyimmersed in the Isopar for about a minute, the sample was removed withtweezers and held above the bowl as it drained. When the rate of Isopardripping from the cellulose acetate reached approximately 1 drop persecond, the cellulose acetate was transferred to a beaker, and the lossin mass of the bowl of Isopar was reported as the Isopar absorbed by thecellulose acetate. The cellulose acetate was then pressed between twowatch glasses or glass plates, and the liberated liquid was dropped intothe beaker. The mass of the liquid liberated represented the Isopar thatcould be recovered by squeezing the cellulose acetate. The squeezedsample was returned to the bowl for another cycle of squeezing for 5repetitions. The sample was found to absorb 4.5 g of Isopar whenpre-wetted with water. Squeezing the saturated sample yielded about 4.3g of material. After squeezing, the sample was able to reabsorb about3.9 g of Isopar.

Table 4 below shows the results of Examples 59-62. The results ofExamples 59-60 demonstrate that, in the absence of water, the modifiedcellulose acetate fibers absorb less hydrocarbons than the unmodifiedfibers. Examples 61-62 demonstrate that in the presence of water, themodified cellulose acetate fibers absorb more hydrocarbons than theunmodified fibers.

TABLE 4 Modifier for Sorbent Initial cellulose condition at Sorbent usedin sorbent Isopar Re-absorption acetate beginning of example (g),capacity of liberated by capacity after Example sorbent test dry basisIsopar (g) pressing (g) pressing (g) 59 Stearic acid Dry 6.8 19 6.5 6.560 None Dry 6.4 25 7.5 7.5 61 Stearic acid Saturated 6.1 7.4 4.3 4.2with water 62 None Saturated 6.2 4.5 4.3 3.9 with water

EQUIVALENTS

While specific embodiments of the subject invention have been discussed,the above specification is illustrative and not restrictive. Manyvariations of the invention will become apparent to those skilled in theart upon review of this specification. Unless otherwise indicated, allnumbers expressing quantities of ingredients, reaction conditions, andso forth used in the specification and claims are to be understood asbeing modified in all instances by the term “about.” Accordingly, unlessindicated to the contrary, the numerical parameters set forth herein areapproximations that can vary depending upon the desired propertiessought to be obtained by the present invention.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed:
 1. A system for removing a target oil from an aqueousfluid stream, comprising: a capture medium that complexes with the oilto form a removable complex that can be removed from the aqueous fluidstream, thereby removing the target oil from the aqueous fluid stream,wherein the capture medium comprises an anchor substrate and a modifiertechnology supported on the anchor substrate, the modifier technologycomplexing with the oil to form the removable complex.
 2. The system ofclaim 1, wherein the anchor substrate has a density greater than that ofthe oil.
 3. The system of claim 1, wherein the anchor substrate has adensity less than that of the oil.
 4. The system of claim 1, wherein theanchor substrate comprises a plurality of loose particles or fibers. 5.The system of claim 1, wherein the anchor substrate is formed as aformed article.
 6. The system of claim 5, wherein the formed article isselected from the group consisting of a sheet, a fibrous network, ascreen, a plurality of elongated fibers, an agglomeration of particulatematter, a mop, a boom, an open-cell foam mass, a closed-cell foam mass,and a swab.
 7. The system of claim 1, wherein the modifier technologycomprises an oleophilic capture substance.
 8. The system of claim 7,wherein the modifier technology further comprises an attachmenttechnology that modifies the surface of the anchor substrate to attachthe oleophilic capture substance thereto.
 9. The system of claim 7,wherein the attachment technology comprises a physical modification ofthe surface of the anchor substrate.
 10. The system of claim 7, whereinthe attachment technology comprises a mechanical mechanism for adheringthe oleophilic capture substance to the surface of the anchor substrate.11. The system of claim 7, wherein the attachment technology comprisesan attachment chemical that attaches the oleophilic capture substance tothe surface of the anchor substrate.
 12. A method for removing a targetoil from an aqueous fluid stream, comprising: preparing a capture mediumcomprising an anchor substrate and a modifier technology supported onthe anchor substrate, wherein the modifier technology complexes with thetarget oil to form a removable complex, deploying the capture mediuminto contact with the target oil, directing the capture medium tocontact the target oil for a contact time such that the capture mediumforms a removable complex with the target oil, removing the removablecomplex from the aqueous fluid stream, thereby removing the target oilfrom the aqueous fluid stream, wherein the step of preparing takes placebefore the step of deploying.
 13. The method of claim 12, wherein theanchor substrate has a density greater than that of the oil.
 14. Themethod of claim 12, wherein the anchor substrate has a density less thanthat of the oil.
 15. The method of claim 12, wherein the anchorsubstrate comprises a plurality of loose particles or fibers.
 16. Themethod of claim 12, wherein the anchor substrate is formed as a formedarticle.
 17. The method of claim 12, wherein the formed article isselected from the group consisting of a sheet, a fibrous network, ascreen, a plurality of elongated fibers, an agglomeration of particulatematter, a mop, a boom, an open-cell foam mass, a closed-cell foam mass,and a swab.
 18. The method of claim 12, wherein the modifier technologycomprises an oleophilic capture substance.
 19. The method of claim 18,wherein the modifier technology further comprises an attachmenttechnology that modifies the surface of the anchor substrate to attachthe oleophilic capture substance thereto.
 20. The system of claim 19,wherein the attachment technology comprises a physical modification ofthe surface of the anchor substrate.
 21. The method of claim 19, whereinthe attachment technology comprises an attachment chemical that attachesthe oleophilic capture substance to the surface of the anchor substrate.22. The method of claim 12, further comprising the step of disposing ofthe removable complex.
 23. A method for removing a target oil from anaqueous fluid stream, comprising: combining the anchor substrate and amodifier technology supported on the anchor substrate to form a capturemedium, wherein the modifier technology complexes with the target oil toform a removable complex, contacting the capture medium with the fluidstream bearing the target oil for a contact time such that the capturemedium forms a removable complex with the target oil, and removing theremovable complex from the aqueous fluid stream, thereby removing thetarget oil from the aqueous fluid stream.
 24. The method of claim 23,wherein the step of combining takes place simultaneously with orfollowing the step of contacting.
 25. The method of claim 23, whereinthe step of contacting further includes a step of directing the fluidstream into contact with the capture medium for the contact time.